Abstract: A plasma generating apparatus includes a feed-through and a cylindrical electrode. The feed-through device is configured to feed a medium frequency (MF) power. The cylindrical electrode includes a plurality of through holes in a wall of the cylindrical electrode and is connected to the feed-through device and configured to receive the MF power from the feed-through device and ionize a gas to generate plasma. The cylindrical electrode includes a main body; and an end cover fixed to one end of the main body. The feed-through device includes a feed-through conductor electrically connected to the cylindrical electrode and configured to feed the MF power to the cylindrical electrode, and a feed-through insulating layer covering at least a part of the feed-through conductor.